<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div>
        <!--1.nth-child(2n)就是把n当作0，1，2然后计算得到2，4  -->
        <!-- 2. nth-child(n+2)，就是包括第2个之后都是这玩意-->
        <ul>
            <li  class="style1">1</li>
            <li  class="style1">2</li>
            <li  class="style1">3</li>
            <li  class="style1">4</li>
            <li  class="style1">5</li>
        </ul>
    </div>
</body>
<style>
.style1:nth-child(n+3){
    color: red;
}
.style1:not(:nth-child(n+2)){
    color: green;
}
</style>
</html>